ELISA tests for the presence of an antigen are known in the prior art. See, for example:    (1) BIOTREND Cheikalien GmbH. General Elisa Kit [Material Safety Data Sheet]. Kaufman, P. et al., Visualization and Measurement of Flow in Two-Dimensional Paper Networks. Lab Chip. 2010, 10, No. 19. 2614-2617    (2) Alpha Diagnostic International Ebola ELISA kit (AE-320500-1) Antibody and visible detection reagents, Alpha Diagnostic International Ebola Virus Nucleoprotein (EVNP15-R),    (3) https://www.abdserotec.com/an-introduction-to-elisa.html.
Additionally, lateral-flow assay devices are known in the prior art. See, for example:    (1) BIOTREND Cheikalien GmbH. General Elisa Kit [Material Safety Data Sheet]. Kaufman, P. et al., Visualization and Measurement of Flow in Two-Dimensional Paper Networks. Lab Chip. 2010, 10, No. 19. 2614-2617    (2) Fu, E., et al., Controlled reagent transport in disposable 2D paper networks. Lab Chip. 2010, 10, No. 7. 918-920    (3) Lu, Q., Wang, X., Hu, X., Cebe, P., Omenetto, F. and Kaplan, D. L. (2010), Stabilization and Release of Enzymes from Silk Films. Macromol. Biosci., 10: 359-368. doi: 10.1002/mabi.200900388    (4) Lutz, B. R., Liang, T., Fu E., Ramachandran, S., Kauffman, P. Yager, P. et al., Dissolvable Fluidic Time Delays for Programming Multi-Step Assays in Instrument-Free Paper Diagnostics. Lab Chip. 2013, 13, No. 14. 2840-2847    (5) Lutz, B. R., et al., Two-dimensional paper networks: programmable fluidic disconnects for multi-step processes in shaped paper. Lab Chip. 2011, 11, No. 24. 4274-4278
Each of the references in this Background Art section is hereby incorporated herein by reference in its entirety. In case of any conflict or ambiguity created by such incorporation by reference, the text of the present Application, devoid of such incorporation, shall govern.